Search Results

With the current trend of including the evaluation of the risk of brain injuries in vehicle crashes due to rotational kinematics of the head, two injury criteria have been introduced since 2013 – BrIC and DAMAGE. BrIC was developed by NHTSA in 2013 and was suggested for inclusion in the US NCAP for frontal and side crashes. DAMAGE has been developed by UVa under the sponsorship of JAMA and JARI and has been accepted tentatively by the EuroNCAP. Although BrIC in US crash testing is known and reported, DAMAGE in tests of the US fleet is relatively unknown. The current paper will report on DAMAGE in NCAP-like tests and potential future frontal crash tests involving substantial rotation about the three axes of occupant heads. Distribution of DAMAGE of three-point belted occupants without airbags will also be discussed. Prediction of brain injury risks from the tests have been compared to the risks in the real world.

Injury Risk Curves are developed from cadaver data for sternal deflections produced by anterior, distributed chest loads for a 25, 45, 55, 65 and 75 year-old Small Female, Mid-Size Male and Large Male based on the variations of bone strengths with age. These curves show that the risk of AIS ≥ 3 thoracic injury increases with the age of the person. This observation is consistent with NASS data of frontal accidents which shows that older unbelted drivers have a higher risk of AIS ≥ 3 chest injury than younger drivers.

An evaluation of the four injury risk curves proposed in the NHTSA NCAP for estimating the risk of AIS≻=3 injuries to the head, neck, chest and AIS≻=2 injury to the Knee-Thigh-Hip (KTH) complex has been conducted. The predicted injury risk to the four body regions based on driver dummy responses in over 300 frontal NCAP tests were compared against those to drivers involved in real-world crashes of similar severity as represented in the NASS. The results of the study show that the predicted injury risks to the head and chest were slightly below those in NASS, and the predicted risk for the knee-thigh-hip complex was substantially below that observed in the NASS. The predicted risk for the neck by the Nij curve was greater than the observed risk in NASS by an order of magnitude due to the Nij risk curve predicting a non-zero risk when Nij = 0. An alternative and published Nte risk curve produced a risk estimate consistent with the NASS estimate of neck injury.

Three-point restraint systems have been installed in vehicles since the early 1960s. However, it wasn't until the automatic protection rule became effective for 1987 Model Year vehicles that manufacturers began installing 3-point restraints with force-limiting shoulder belts and frontal airbags for the driver and right front passenger. This was the first time that all vehicle manufacturers had to certify that their cars would meet the 50th percentile, adult male protection requirements in the 48 km/h frontal, rigid-barrier test specified in FMVSS 208. To assess the effectiveness of these certified 3-point restraint systems, a search was done of the 1988-2005 NASS data for 3-point belted, front outboard-seated, adult occupants in passenger vehicles that were equipped with airbags and that were involved in frontal, towaway collisions.

Static out-of-position tests were performed to identify the potential for injury as a function of position, airbag type and vehicle seat characteristics. Seat and door mounted airbags, head curtains and head tubes were evaluated. Out-of-position testing was carried out with the Hybrid III 3 year old, 6 year old and the TNO Q3 3 year old child dummies. In-position tests and a dynamic test were conducted to monitor child seat and airbag interactions and to confirm that properly restrained children would not be exposed to undue risk from a deploying side airbag. Results of the out-of-position testing suggest that current side airbag designs may cause serious and/or fatal neck and chest injuries. In-position static testing with child seats suggested a potential for intrusion into the child occupant space leading to structural damage of the car seat.

Historically, assessments of frontal crash safety have been based primarily on the measured responses of 50th percentile male dummies in relatively high speed vehicle crashes against a rigid flat barrier. Under such test conditions, the ability of supplementary airbag systems to greatly reduce head injury potential is clearly evident in crash tests performed by Transport Canada and others. However, significant segments of the driving population travel routinely with their seats positioned ahead of the nominal mid-position used in 50th percentile male dummy tests. Moreover, most frontal impacts can be expected to produce softer vehicle deceleration signatures than those produced in flat rigid wall tests. The necessity of broadening the range of regulated crash conditions to which vehicles fitted with airbag systems are subjected is highlighted in crash tests performed by Transport Canada using 5th percentile female Hybrid III tests, with seats placed in their most forward positions.

Detailed knowledge of the load paths at the vehicle/dummy interface in side impact crash tests is an essential component in the evaluation of side impact protection systems. In the laboratory, measurements of the external crush and occupant compartment intrusion profiles may be made with great precision. Recent advances in portable electronic measurement instruments have resulted in such procedures also being possible in the field. This paper describes the use of a total station to obtain these data for real-world side impact collisions. This information is likely to provide additional insight into specific injury mechanisms in such crashes.

As a consequence of various federal and provincial initiatives to promote the use of seat belts in Canada, the wearing rate of seat belts among front outboard passenger car occupants is now estimated at 90 percent. Accordingly, the vast majority of air bag deployments in Canada involve restrained occupants. In order to gain a better understanding of the field performance of air bag systems, Transport Canada recently initiated an m-depth study of motor vehicle collisions involving air bag deployments. To date, investigations have been completed on 242 such collisions. While the preliminary data suggest that supplementary air bag systems provide considerable added protection against serious head injuries in moderate and high severity frontal crashes, they also suggest that, in low severity crashes, deployment of an air bag system may expose belted occupants to unnecessary injury risk from the air bag itself.

Drawing on field data gathered during the course of Transport Canada's Fully Restrained Occupant Study (FROS), the current limits of protection afforded vehicle occupants restrained by conventional three-point seat-belt assemblies in side impacts are examined. The sample under consideration comprises 98 restrained passenger vehicle occupants involved either in a near side or a far side impact, each of whom sustained at least one injury at the AIS 2 or greater severity level (1976 AIS Dictionary). A detailed description of the pattern of injury to this subset of occupants and the damage sustained by the vehicle is presented. The principal mechanisms of injury for various body region groupings are discussed, with special attention being given to the incidence of side compartment intrusion. Other factors influencing injury potential such as occupant age and vehicle size are also discussed.

This paper summarizes the findings of a study undertaken by Transport Canada to examine the primary mechanisms of injury to front seat occupants restrained by conventional three-point seat belt assemblies. The study involved the early retrospective investigation of collisions, in defined geographic areas across Canada, in which at least one occupant involved was fully restrained. The pattern of injury to 314 full restrained occupants who sustained at least one injury at the AIS 2 or greater severity level is examined in the present paper. Overall, the head/face and chest were found to be the most frequently injured body regions. In the case of drivers, facial injuries were invariably associated with the steering wheel, whereas head injury was more likely to be associated with interior side and roof structures. Injuries to the shoulder/chest and pelvic/abdomen regions among drivers were usually associated with direct contact with either the steering wheel or the interior side surfaces.